/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 * 
 *   http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

#ifndef NET_INSTAWEB_REWRITER_PUBLIC_JS_DISABLE_FILTER_H_
#define NET_INSTAWEB_REWRITER_PUBLIC_JS_DISABLE_FILTER_H_

#include "net/instaweb/rewriter/public/common_filter.h"
#include "net/instaweb/rewriter/public/rewrite_driver.h"
#include "net/instaweb/rewriter/public/script_tag_scanner.h"
#include "pagespeed/kernel/base/basictypes.h"
#include "pagespeed/kernel/base/string.h"
#include "pagespeed/kernel/html/html_element.h"
#include "pagespeed/kernel/html/html_filter.h"
#include "pagespeed/kernel/http/user_agent_matcher.h"

namespace net_instaweb {

// Disables javscript by converting input html:
//   <script src="1.js">var a = 1...</script>
// to:
//   <noscript disabled="true">
//     <script src="1.js">var a = 1...</script>
//   </noscript>
//
class JsDisableFilter : public CommonFilter {
 public:
  explicit JsDisableFilter(RewriteDriver* driver);
  ~JsDisableFilter() override;

  static const char kEnableJsExperimental[];
  static const char kElementOnloadCode[];

  void DetermineEnabled(GoogleString* disabled_reason) override;

  const char* Name() const override { return "JsDisableFilter"; }

  ScriptUsage GetScriptUsage() const override { return kWillInjectScripts; }

 private:
  void StartDocumentImpl() override;

  void StartElementImpl(HtmlElement* element) override;

  void EndElementImpl(HtmlElement* element) override;

  void EndDocument() override;

  // Inserts the experimental js enable/disable code.
  void InsertJsDeferExperimentalScript();

  // Insert meta tag with 'X-UA-Compatible'. This will avoid IE going to quirks
  // mode. More information about this can be found in
  // http://webdesign.about.com/od/metataglibraries/p/x-ua-compatible-meta-tag.htm
  void InsertMetaTagForIE(HtmlElement* element);

  ScriptTagScanner script_tag_scanner_;
  int index_;
  bool ie_meta_tag_written_;

  DISALLOW_COPY_AND_ASSIGN(JsDisableFilter);
};

}  // namespace net_instaweb

#endif  // NET_INSTAWEB_REWRITER_PUBLIC_JS_DISABLE_FILTER_H_
